Shaped charge perforating apparatus for use in wells and the like



June 18, 1957 DELACO J. SHAPED CHARGE PERFORAT APP TUS I FOR USE IN LfifAND THE L K Filed f "F 50, 195,1,1-13

I V NTOR.

ATTORNEYS.

SHAPED CHARGE PERFORATING APPARATUS FOR USE IN WELLS AND THE LIKE Jacques Delacour, Paris, France, assignor, by mesne assignments, to Borg-Warner Corporation, Chicago, Ill., a corporation of Illinois Application October 30, 1951, Serial No. 253,823

Claims priority, application France December 18, 1950 2 Claims. (Cl. 102-20) The present invention relates to shaped explosive charge devices for carrying out perforating operations in wells and the like, and more particularly to apparatus of this character which is less subject to damage than the apparatus available heretofore.

The copending application Serial No. 128,950, filed November 23, 1949, by Marcel Schlumberger, for Apparatus for Perforating Well Casings by Means of Shaped Charges discloses perforating apparatus comprising a hollow elongated, enclosed housing of substantially uniform wall thickness having ports therein adapted to be tightly closed by suitable cap means. Shaped charges with liners are mounted in containers which are adapted to be inserted through the ports. On the inside wall of the housing, opposite each of the ports therein, are provided means for supporting the rear ends of the charge containers and the forward ends of the latter are supported in the housing ports and are retained therein by the cap means.

It is an object of the invention, accordingly, to provide new and improved shaped charge perforating apparatus of the above character havingimproved means for mounting and supporting the charges in their housing.

In accordance with the invention, the housing in which the charges are mounted is so constructed that its inner wall is substantially polygonal in transverse section, the outer wall preferably being cylindrical. Since the charges should desirably be angularly displaced with respect to one another about the longitudinal axis of the housing, the sides of the polygon formed by the interior wall of the housing should preferably be angularly displaced in corresponding fashion. Specifically, the polygonal surface thus formed may comprise roughly a triangular or hexagonal prism with very rounded angles.

With this construction, the side wall of the housing is not of uniform thickness but varies in thickness from minimum values in the vicinity of the angles of the polygon, to maximum values intermediate adjacent angles of the polygon. By forming the ports in the housing at locations where the wall thickness is a maximum a greater length of thread and better operating thread may be provided than has previously been possible, for securing the caps in the housing ports. Further, the thickened portions of the housing provide reenforcing where it is most needed to withstand the greatest stresses caused by explosion of the charges.

Other objects and characteristics of the invention will appear in the course of the following description of several typical embodiments, taken in conjuction with the accompanying drawings, in which:

Fig. 1 is a View in longitudinal section through a portion of one form of shaped charge perforating apparatus constructed according to the invention;

Fig. 2 is a view in transverse section taken along line 22 of Fig. 1; and

Fig. 3 is a view in transverse section of another embodiment of the invention.

In Fig. 1 is shown a portion of a shaped charge per- V Patented June 18, 1957 forating apparatus which may be of the general type described in the aforementioned application Serial No. 128,950, for example. It differs, however, in that the wall of the perforator housing 10 is not of uniform thickness, but has an interior wall surface which is substantially polygonal in transverse section as shown in Fig. 2, its outer Wall surface being cylindrical. Roughly, the interior wall surface of the housing 10 in transverse section is an isosceles triangle having the sides 11, 12 and 13 with rounded off apices 14, 15 and 16.

Formed in the housing wall adjacent the side 12 is a port 17, through which a shaped charge assembly 18 is adapted to be inserted. The port 17 is interiorly threaded and is adapted to be closed by a threaded cap 19 which also serves to retain the charge assembly 18 in fixed position. The rear end of the charge assembly 18 is supported in a recess 20 formed in the inner wall of the housing 10 adjacent the apex angle 14, as shown. Detonation of the charge may be effected in any desired manner, as, for example, by a Primacord fuse 21 extending through a slot 22 at the rear end of the charge assembly 18. The fuse may be set off by a blasting cap (not shown) or by other suitable means.

While only one housing port 17 is shown in Figs. 1 and 2, preferably, a plurality of such ports will be formed in the housing 10, successive ports being angularly displaced from each other in the form of a spiral array. Facing each port 17 will be a shaped charge assembly 18 retained in position by a threaded cap 19.

By forming the ports in the sides 11, 12 and 13 of the housing 10 where the wall thickness is a maximum, it will be understood that a greater length of thread may be provided for securing the cap 19 in the port 17 so that a more effective closure is formed. Further, the thickened wall portions intermediate the apex angles 14, 15 and 16 provide additional strengthening for the housing 10 at the very places which have to withstand the highest stresses during the explosion of the charges. In addition, the essentially triangular shape of the interior wall in transverse section enables the charges to be mounted in different azimuths perpendicular to the wall sides 11, 12 and 13.

In the form of the invention shown in Fig. 3, the interior wall of the housing 10 is substantially hexagonal in transverse section, the apex angles being rounded ch as shown. Aside from this difference, the apparatus is the same in construction and operation as the modification shown in Fig. 2. With the hexagonal shape shown, it will be understood that the charges in the housing 10 may be angularly displaced 60 apart.

From the foregoing description, it will be apparent that the invention provides new and improved shaped charge perforating apparatus which is less subject to damage than the appartus available prior to the invention. By constructing the interior wall of the perforator housing to be substantially polygonal in transverse section and forming the housing ports in the wall portions in the sides of the polygon, a better thread can be provided for securing the caps to the ports. Also, the thickened portions of the housing Wall provide strengthening thereof to withstand the highest stresses developed upon explosion of the charges.

Obviously, the several embodiments that have been described above are susceptible of modification within the spirit of the invention. In particular, the inner wall of the perforator housing, in transverse section, may have the form of any polygon, regular or otherwise, instead of the roughly triangular or hexagonal forms shown. The invention, therefore, is not to be limited save as defined in the following claims.

, a 3 I claim: 1. In shaped charge perforating apparatus for use in a deep narrow bore hole, the combination of an enclosed, tubular, pressureeresistant housing adapted to be.

moved through the bore hole and having a substantially cylindrical outer Wall surface and an inner wall surface provided with at least one portion of substantially lesser curvature than said outerwall, said one portion and the adjacent portion of said outer wall' surface bounding a thickened housing Wall'portion, means forming an interiorly threaded port in said thickenend Wall portion, a shaped explosive charge assembly mounted in said housing with the lined cavity thereof facing said port such that upon detonation of said shaped explosive charge the forces of explosion are directed partly against said inner Wall surface, and externally threaded cap means threadedly secured in said port and retaining said shaped charge assembly in position.

'aveaoaa 7 2. Apparatus as set forth in claim 1 in which the said one portionv of said inner wall surface is relatively fiat and forms one side of a polygon.

References Cited in the file of this patent UNITED STATES PATENTS 2,092,294 Turecheck Sept. 7, 1937 2,494,256 Muskat et-al. Jan. 10, 1950 OTHER REFERENCES Article by W. T. Box and R. F. Merklejohn published 

